I've recently noticed that the grids and the masks are not lining up in most aspect ratios. I usually have custom grids, but I checked this with default install and no user grids to make sure it wasn't something with my custom file. I have not tested all, but I just tried the following in 2023.2.002:

3840x2160, 1920x1080, 4096x2160, 2048x858 and 1998x1080 and I tested 2.39, 2.35, 2.40 and 2:1.

In all cases except 1998x1080 at 2.39 the grids and masks are not on the same pixel, and it's also not a consistent amount, but as an example a 2.39 grid in 3840x2160 is about half a pixel higher than the mask on the top and about 3/4 higher on the bottom, so it seems like the whole grid needs to move down to match the mask.

And in testing this I have now seen that the mask and the Pan Scan aspect ratio are also not the same. In that same example the mask is 1 pixel bigger (?) than the mask on the top but the bottom is the same. A couple of example stills are attached.

It's a bit disconcerting as I'm now not sure which is correct and makes it hard to argue when I get QC reports with incorrect line counts.